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Obfuscation Mode
The Obfuscation mode is a simple but quite efficient trick to let the VoIP pass without being recognised by router that could perform Quality of Service degrading the call.
It's not known to be a perfect mask and it aims not to be one, still it works fine until now and our suggestion is to keep it enabled as by default,
Obfuscation Key
The key used by the obfuscator can be an arbitrary one, still "9" is the default value. It doesn't matter which number you put in here as long as it is the very same one you set up on the client side.
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If the Obfuscation Key value is not the same on both client's account and server's one, then the call won't be placed properly and it might end suddenly voiceless. |
Keep-alive Enabled
To be reachable the client must set up a stable socket to the server. Each client sends a "keep alive" request to the server it's connected to in order to keep up the socket. This is necessary as the TCP socket has an idle timeout after which the socket is closed. Some aggressive network devices can short the standard timeout under 10 minutes, making impossible for the client to send the "keep alive" request because it would always be late (the client sends its request every 10 minutes or so).
In order to avoid the socket break caused by such aggressive network devices, you can set up a server side "keep alive" request that is going to be performed every 3 minutes. In this way you can be sure that the socket and thus the connection would remain up and stable under every circumstances.
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The downside of this option is that there will be some more traffic on the socket (each passage of the request is 1.8 KiloByte, thus you can count almost 3.6 KB of traffic every 3 minutes) |
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This option can afflict the battery life since more traffic means more radio transmission and on same devices the radio wouldn't have a proper timeout for going idle. |
You can configure the general keep-alive timeout in the NAT configuration form. Please read PSAM 2.4 Asterisk advanced configurations to get informations about it.
After you completed to fill the form please click on the Create icon at the page's bottom.
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